Apparatus for and method of suppressing infrared radiation emitted from gas turbine engine

An apparatus for suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof during engine operation comprises a dual purpose ejector vane assembly operatively attached to said engine for introducing cooling ambient air into the hot engine exhaust gases and hiding said hot metal parts and means attaching said vane assembly to said engine, said vane assembly comprising, a tubular duct structure for receiving and confining said engine exhaust gases, and ejector means providing a plurality of streams of cooling ambient air completely across said duct structure to break the exhaust gases confined by the duct structure during engine operation into a plurality of separate exhaust gas streams and provide optimum mixing of said streams of cooling ambient air with said exhaust gases completely across said duct structure, said duct structure being defined by two pairs of opposed walls wherein one of said pair of opposed walls has an undulating configuration, said ejector means comprising a plurality of elongated slot means in each wall of said one pair of walls, said ejector means further comprising a plurality of hollow airfoil-shaped vanes disposed in said duct structure between and supported by said other pair of walls, said vanes dividing the volume between said one pair of walls into a plurality of chambers of substantially equal volume, each of said vanes having opposite open end portions extending through said other pair of walls to provide open ends exposed to ambient air and having integral slot means, each vane serving to introduce additional cooling ambient air through its open ends and substantially perpendicular to said other pair of walls, said additional cooling ambient air being turned by said vanes and provided through said slot means in each vane into said exhaust gases at locations between said one pair of walls and in a plurality of roughly parallel streams, each of said airfoil-shaped vanes having opposed cooperating walls and said slot means in each vane comprising a plurality of elongated slot means in each of the cooperating walls of a vane, each wall of said one pair of walls of said duct structure and each wall of said cooperating walls of each of said vanes being comprised of a plurality of heat transfer panel assemblies defined as an integral part of its wall, said heat transfer panel assemblies having said slot means defined therein as a part thereof, each of said heat transfer panel assemblies comprising a pair of wall portions having an undulating strip fixed therebetween in sandwiched relation and the space between said wall portions defined by said undulating strip defining a slot means in an associated panel assembly, said undulating strip having a substantially rectangular wave form when viewed from an end thereof and having openings therein which serve as turbulators aiding in the cooling of their associated panel by the cooling ambient air flowing therethrough.

An apparatus for suppressing infrared radiation emitted from hot metal parts at the aft end of a gas turbine engine and from the exhaust gas plume thereof during engine operation comprising a dual purpose ejector vane assembly operatively attached to said engine for introducing cooling ambient air into the hot engine exhaust gases and hiding said hot metal parts and means attaching said vane assembly to said engine, said vane assembly comprising, a tubular duct structure for receiving and confining said engine exhaust gases, and ejector means providing a plurality of streams of cooling ambient air comletely across said duct structure to break the exhaust gases confined by said duct structure during engine operation into a plurality of separate exhaust gas streams and provide optimum mixing of said streams of cooling ambient air with said exhaust gases completely across said duct structure, said duct structure being defined by two pairs of opposed walls wherein one of said pairs of opposed walls has an undulating configuration, said ejector means comprising a plurality of elongated slot means in each wall of said one pair of walls, said ejector means further comprising a plurality of hollow airfoil-shaped vanes disposed in said duct structure between and supported by said other pair of walls, said vanes dividing the volume between said one pair of walls into a plurality of chambers of substantially equal volume, each of said vanes having opposite open end portions extending through said other pair of walls to provide open ends exposed to ambient air and having integral slot means, each vane serving to introduce additional cooling ambient air through its open ends and substantially perpendicular to said other pair of walls, said additional cooling ambient air being turned by said vanes and provided through said slot means in said vane into said exhaust gases at locations between said one pair of walls and in a plurality of roughly parallel streams, each of said vanes having means for changing the area of its opposite open end portions to thereby control the amount of additional cooling ambient air introduced through said open ends.